In Situ Monitoring and Bioluminescence Kinetics of Pseudomonas fluorescens M3A Bioluminescent Reporter with Bacteriophage ΦS1

Food spoilage and the associated organisms are a continuing concern for the food industry. The microorganisms involved with food spoilage in pasteurized milk can be introduced in a variety of ways, which include those that survive pasteurization and/or are introduced post-pasteurization. The use of bacteriophages for therapeutic regimens and as a method for the biocontrol of food-borne pathogens has been widely studied and applied; however, their use in the biocontrol against spoilage organisms is in its nascency. Bioluminescent bacteria offer the ability to act as cell-death reporters. In the case of using bacteriophage against spoilage-associated bacteria, cell death results in the loss of bioluminescence. In this study, a bioluminescent Pseudomonas species, Pseudomonas fluorescens M3A, was used to monitor the efficacy of the bacteriophage-associated biocontrol system within laboratory bacterial growth broth and fluid milk using bacteriophage ΦS1. Utilizing a bioluminescence kinetic assay with ten-fold serially diluted P. fluorescens M3A and bacteriophage ΦS1, data demonstrated rapid inactivation of bacterial growth, and at low bacteriophage titers. Cell death was indicated by the loss of bacterial bioluminescence. These data help to support the application of bacteriophage-based technologies against spoilage-associated bacteria to prolong shelf life in the event of microbial growth.